settings trim: remove dead settings, upstream remnants, JSON/Clash subscriptions

Per SETTINGS-AUDIT (all three tiers approved 2026-10-23):

Dead settings:
- panelOutbound, ipLimitAllowlist (+ orphan parser job), outboundDownThreshold
- tg fake events outbound.down/outbound.up/xray.crash (no publisher in lite)
- phantom routing sub-tabs (Happ/Clash/Incy) and subJsonRules direct-rules tab
  (no backend keys); subHideSettings moved to the subscription info tab first

Upstream remnants:
- ldap* / smtp* model+schema keys, EmailNotifications orphan component
- twoFactorEnable/twoFactorToken + login-page probe (no backend handler)
- externalTrafficInform*

Newly approved removals:
- JSON subscription family (producer, routes, UA auto-detect, mux/finalmask/
  observatory) and Clash subscription family (producer, routes, UA detect)
- SubBalancer (table, service, controller, settings tab)
- subThemeDir (subscription page falls back to the built-in template)
- datepicker jalalian option (gregorian only; Persian picker removed)

JSON/Clash endpoints now 404; link-format output pinned by regression tests.
Guarded keys untouched: webListen/webPort/webBasePath/certs, tg* chain,
expireDiff/trafficDiff/tgBotProxy, subHideSettings, pageSize/tgLang.

frontend/src/pages/inbounds/qr/QrCodeModal.tsx

@@ -55,7 +55,6 @@ export default function QrCodeModal({
   const [amneziawgConfigs, setAmneziawgConfigs] = useState<string[]>([]);
   const [amneziawgLinks, setAmneziawgLinks] = useState<string[]>([]);
   const [subLink, setSubLink] = useState('');
-  const [subJsonLink, setSubJsonLink] = useState('');
   const [activeKey, setActiveKey] = useState<string[]>([]);
 
   // Building the links is a pure function of the props, so it runs during
@@ -145,13 +144,10 @@ export default function QrCodeModal({
 
     const subId = client?.subId;
     let nextSub = '';
-    let nextSubJson = '';
     if (subSettings?.enable && subId) {
       nextSub = (subSettings.subURI || '') + subId;
-      nextSubJson = subSettings.subJsonEnable ? (subSettings.subJsonURI || '') + subId : '';
     }
     setSubLink(nextSub);
-    setSubJsonLink(nextSubJson);
   }
 
   const qrItems = useMemo<QrItem[]>(() => {
@@ -159,13 +155,6 @@ export default function QrCodeModal({
     if (subLink) {
       items.push({ key: 'sub', header: t('subscription.title'), value: subLink });
     }
-    if (subJsonLink) {
-      items.push({
-        key: 'sub-json',
-        header: `${t('subscription.title')} (JSON)`,
-        value: subJsonLink,
-      });
-    }
     links.forEach((link, idx) => {
       items.push({ key: `l${idx}`, header: link.remark || `Link ${idx + 1}`, value: link.link });
     });
@@ -202,16 +191,7 @@ export default function QrCodeModal({
       }
     });
     return items;
-  }, [
-    subLink,
-    subJsonLink,
-    links,
-    wireguardConfigs,
-    wireguardLinks,
-    amneziawgConfigs,
-    amneziawgLinks,
-    t,
-  ]);
+  }, [subLink, links, wireguardConfigs, wireguardLinks, amneziawgConfigs, amneziawgLinks, t]);
 
   const collapseItems: CollapseProps['items'] = useMemo(
     () =>